One example of a rotary application head includes a housing and a cylinder chamber in the housing, wherein the cylinder chamber includes a cylinder slide rotably drivably supported. The application head also includes at least one supply aperture for introducing a medium into the cylinder chamber and a nozzle for ejecting the medium, which nozzle can be controlled by the cylinder slide and extends transversely to the direction of movement of the length of material. The application head may be mounted in a non-contacting way with respect to the length of material.
An application head of the foregoing type is disclosed in U.S. Pat. No. 6,024,299 wherein a cylinder slide is shown which, in an axial region comprising the supply aperture, includes a recess extending over the entire circumference. At least in this axial region, no exit nozzle opening controlled by the cylinder slide can be provided. This means that, in this axial region, the exit nozzle apertures must be arranged at an undesirably long distance. In addition, the cylinder slide is relatively short. If it had a greater length, it would be necessary to provide a plurality of supply apertures. As a result, the above-mentioned problem along the nozzle would be multiplied accordingly.
A further application head of this type is known from DE 197 57 238 C2 wherein the surface grooves are formed by axis-parallel grooves on the cylinder slide or by parallel helical grooves on the cylinder slide. Both embodiments are said to achieve the application of an economical mount of extremely uniformly distributed liquid medium on the length of material.
Application heads of the above-mentioned type are widely used in those cases where lengths of material have to be laminated on to a substrate. To reduce the specific consumption of liquid medium to a minimum and to ensure an extremely uniform distribution of the medium, the medium is applied intermittently in order to achieve a grid-like application image. In order to permit a high transport speed for the length of material, the application of medium in the direction of movement of the length of material has to take place at a high frequency, with the grid points transverse to the direction of movement of the length of material having to be positioned as closely as possible to one another.